NewFailoverClient seems to not support TLS

[mdouchement]

NewFailoverClient seems to not support TLS, a tcpdump shows plaintext auth.

Expected Behavior

It should PING the Redis server.

Current Behavior

$ go run .
redis: 2021/04/20 10:11:24 sentinel.go:682: sentinel: discovered new sentinel="r1.example.org:26379" for master="master"
redis: 2021/04/20 10:11:24 sentinel.go:643: sentinel: new master="master" addr="r0.example.org:6379"
panic: read: connection reset by peer

Steps to Reproduce

package main

import (
	"context"
	"crypto/tls"
	"fmt"
	"time"

	"github.com/go-redis/redis/v8"
)

func main() {
	rdb := redis.NewFailoverClient(&redis.FailoverOptions{
		MasterName: "master",
		SentinelAddrs: []string{
			"r0.example.org:26379",
			"r1.example.org:26379",
		},
		SentinelPassword: "strongpassword",
		Password:         "strongpassword",
		TLSConfig:        &tls.Config{},
		DB:               1,
	})

	err := rdb.Ping(context.Background()).Err()
	if err != nil {
		panic(err)
	}
}

Context (Environment)

• github.com/go-redis/redis/v8 v8.8.2
• redis_version:6.2.1

Detailed Description

Possible Implementation